// Copyright 2017 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// YUV->RGB conversion functions

//

// Author: Skal (pascal.massimino@gmail.com)

#include "src/dsp/yuv.h"

#if defined(WEBP_USE_NEON)

#include <assert.h>

#include <stdlib.h>

#include "src/dsp/neon.h"

//-----------------------------------------------------------------------------

static uint8x8_t ConvertRGBToY_NEON(const uint8x8_t R,

                                    const uint8x8_t G,

                                    const uint8x8_t B) {

  const uint16x8_t r = vmovl_u8(R);

  const uint16x8_t g = vmovl_u8(G);

  const uint16x8_t b = vmovl_u8(B);

  const uint16x4_t r_lo = vget_low_u16(r);

  const uint16x4_t r_hi = vget_high_u16(r);

  const uint16x4_t g_lo = vget_low_u16(g);

  const uint16x4_t g_hi = vget_high_u16(g);

  const uint16x4_t b_lo = vget_low_u16(b);

  const uint16x4_t b_hi = vget_high_u16(b);

  const uint32x4_t tmp0_lo = vmull_n_u16(         r_lo, 16839u);

  const uint32x4_t tmp0_hi = vmull_n_u16(         r_hi, 16839u);

  const uint32x4_t tmp1_lo = vmlal_n_u16(tmp0_lo, g_lo, 33059u);

  const uint32x4_t tmp1_hi = vmlal_n_u16(tmp0_hi, g_hi, 33059u);

  const uint32x4_t tmp2_lo = vmlal_n_u16(tmp1_lo, b_lo, 6420u);

  const uint32x4_t tmp2_hi = vmlal_n_u16(tmp1_hi, b_hi, 6420u);

  const uint16x8_t Y1 = vcombine_u16(vrshrn_n_u32(tmp2_lo, 16),

                                     vrshrn_n_u32(tmp2_hi, 16));

  const uint16x8_t Y2 = vaddq_u16(Y1, vdupq_n_u16(16));

  return vqmovn_u16(Y2);

}

static void ConvertRGB24ToY_NEON(const uint8_t* rgb, uint8_t* y, int width) {

  int i;

  for (i = 0; i + 8 <= width; i += 8, rgb += 3 * 8) {

    const uint8x8x3_t RGB = vld3_u8(rgb);

    const uint8x8_t Y = ConvertRGBToY_NEON(RGB.val[0], RGB.val[1], RGB.val[2]);

    vst1_u8(y + i, Y);

  }

  for (; i < width; ++i, rgb += 3) {   // left-over

    y[i] = VP8RGBToY(rgb[0], rgb[1], rgb[2], YUV_HALF);

  }

}

static void ConvertBGR24ToY_NEON(const uint8_t* bgr, uint8_t* y, int width) {

  int i;

  for (i = 0; i + 8 <= width; i += 8, bgr += 3 * 8) {

    const uint8x8x3_t BGR = vld3_u8(bgr);

    const uint8x8_t Y = ConvertRGBToY_NEON(BGR.val[2], BGR.val[1], BGR.val[0]);

    vst1_u8(y + i, Y);

  }

  for (; i < width; ++i, bgr += 3) {  // left-over

    y[i] = VP8RGBToY(bgr[2], bgr[1], bgr[0], YUV_HALF);

  }

}

static void ConvertARGBToY_NEON(const uint32_t* argb, uint8_t* y, int width) {

  int i;

  for (i = 0; i + 8 <= width; i += 8) {

    const uint8x8x4_t RGB = vld4_u8((const uint8_t*)&argb[i]);

    const uint8x8_t Y = ConvertRGBToY_NEON(RGB.val[2], RGB.val[1], RGB.val[0]);

    vst1_u8(y + i, Y);

  }

  for (; i < width; ++i) {   // left-over

    const uint32_t p = argb[i];

    y[i] = VP8RGBToY((p >> 16) & 0xff, (p >> 8) & 0xff, (p >>  0) & 0xff,

                     YUV_HALF);

  }

}

//-----------------------------------------------------------------------------

// computes: DST_s16 = [(C0 * r + C1 * g + C2 * b) >> 16] + CST

#define MULTIPLY_16b_PREAMBLE(r, g, b)                           \

  const int16x4_t r_lo = vreinterpret_s16_u16(vget_low_u16(r));  \

  const int16x4_t r_hi = vreinterpret_s16_u16(vget_high_u16(r)); \

  const int16x4_t g_lo = vreinterpret_s16_u16(vget_low_u16(g));  \

  const int16x4_t g_hi = vreinterpret_s16_u16(vget_high_u16(g)); \

  const int16x4_t b_lo = vreinterpret_s16_u16(vget_low_u16(b));  \

  const int16x4_t b_hi = vreinterpret_s16_u16(vget_high_u16(b))

#define MULTIPLY_16b(C0, C1, C2, CST, DST_s16) do {              \

  const int32x4_t tmp0_lo = vmull_n_s16(         r_lo, C0);      \

  const int32x4_t tmp0_hi = vmull_n_s16(         r_hi, C0);      \

  const int32x4_t tmp1_lo = vmlal_n_s16(tmp0_lo, g_lo, C1);      \

  const int32x4_t tmp1_hi = vmlal_n_s16(tmp0_hi, g_hi, C1);      \

  const int32x4_t tmp2_lo = vmlal_n_s16(tmp1_lo, b_lo, C2);      \

  const int32x4_t tmp2_hi = vmlal_n_s16(tmp1_hi, b_hi, C2);      \

  const int16x8_t tmp3 = vcombine_s16(vshrn_n_s32(tmp2_lo, 16),  \

                                      vshrn_n_s32(tmp2_hi, 16)); \

  DST_s16 = vaddq_s16(tmp3, vdupq_n_s16(CST));                   \

} while (0)

// This needs to be a macro, since (128 << SHIFT) needs to be an immediate.

#define CONVERT_RGB_TO_UV(r, g, b, SHIFT, U_DST, V_DST) do {     \

  MULTIPLY_16b_PREAMBLE(r, g, b);                                \

  MULTIPLY_16b(-9719, -19081, 28800, 128 << SHIFT, U_DST);       \

  MULTIPLY_16b(28800, -24116, -4684, 128 << SHIFT, V_DST);       \

} while (0)

static void ConvertRGBA32ToUV_NEON(const uint16_t* rgb,

                                   uint8_t* u, uint8_t* v, int width) {

  int i;

  for (i = 0; i + 8 <= width; i += 8, rgb += 4 * 8) {

    const uint16x8x4_t RGB = vld4q_u16((const uint16_t*)rgb);

    int16x8_t U, V;

    CONVERT_RGB_TO_UV(RGB.val[0], RGB.val[1], RGB.val[2], 2, U, V);

    vst1_u8(u + i, vqrshrun_n_s16(U, 2));

    vst1_u8(v + i, vqrshrun_n_s16(V, 2));

  }

  for (; i < width; i += 1, rgb += 4) {

    const int r = rgb[0], g = rgb[1], b = rgb[2];

    u[i] = VP8RGBToU(r, g, b, YUV_HALF << 2);

    v[i] = VP8RGBToV(r, g, b, YUV_HALF << 2);

  }

}

static void ConvertARGBToUV_NEON(const uint32_t* argb, uint8_t* u, uint8_t* v,

                                 int src_width, int do_store) {

  int i;

  for (i = 0; i + 16 <= src_width; i += 16, u += 8, v += 8) {

    const uint8x16x4_t RGB = vld4q_u8((const uint8_t*)&argb[i]);

    const uint16x8_t R = vpaddlq_u8(RGB.val[2]);  // pair-wise adds

    const uint16x8_t G = vpaddlq_u8(RGB.val[1]);

    const uint16x8_t B = vpaddlq_u8(RGB.val[0]);

    int16x8_t U_tmp, V_tmp;

    CONVERT_RGB_TO_UV(R, G, B, 1, U_tmp, V_tmp);

    {

      const uint8x8_t U = vqrshrun_n_s16(U_tmp, 1);

      const uint8x8_t V = vqrshrun_n_s16(V_tmp, 1);

      if (do_store) {

        vst1_u8(u, U);

        vst1_u8(v, V);

      } else {

        const uint8x8_t prev_u = vld1_u8(u);

        const uint8x8_t prev_v = vld1_u8(v);

        vst1_u8(u, vrhadd_u8(U, prev_u));

        vst1_u8(v, vrhadd_u8(V, prev_v));

      }

    }

  }

  if (i < src_width) {  // left-over

    WebPConvertARGBToUV_C(argb + i, u, v, src_width - i, do_store);

  }

}

//------------------------------------------------------------------------------

extern void WebPInitConvertARGBToYUVNEON(void);

WEBP_TSAN_IGNORE_FUNCTION void WebPInitConvertARGBToYUVNEON(void) {

  WebPConvertRGB24ToY = ConvertRGB24ToY_NEON;

  WebPConvertBGR24ToY = ConvertBGR24ToY_NEON;

  WebPConvertARGBToY = ConvertARGBToY_NEON;

  WebPConvertARGBToUV = ConvertARGBToUV_NEON;

  WebPConvertRGBA32ToUV = ConvertRGBA32ToUV_NEON;

}

//------------------------------------------------------------------------------

#define MAX_Y ((1 << 10) - 1)    // 10b precision over 16b-arithmetic

static uint16_t clip_y_NEON(int v) {

  return (v < 0) ? 0 : (v > MAX_Y) ? MAX_Y : (uint16_t)v;

}

static uint64_t SharpYUVUpdateY_NEON(const uint16_t* ref, const uint16_t* src,

                                     uint16_t* dst, int len) {

  int i;

  const int16x8_t zero = vdupq_n_s16(0);

  const int16x8_t max = vdupq_n_s16(MAX_Y);

  uint64x2_t sum = vdupq_n_u64(0);

  uint64_t diff;

  for (i = 0; i + 8 <= len; i += 8) {

    const int16x8_t A = vreinterpretq_s16_u16(vld1q_u16(ref + i));

    const int16x8_t B = vreinterpretq_s16_u16(vld1q_u16(src + i));

    const int16x8_t C = vreinterpretq_s16_u16(vld1q_u16(dst + i));

    const int16x8_t D = vsubq_s16(A, B);       // diff_y

    const int16x8_t F = vaddq_s16(C, D);       // new_y

    const uint16x8_t H =

        vreinterpretq_u16_s16(vmaxq_s16(vminq_s16(F, max), zero));

    const int16x8_t I = vabsq_s16(D);          // abs(diff_y)

    vst1q_u16(dst + i, H);

    sum = vpadalq_u32(sum, vpaddlq_u16(vreinterpretq_u16_s16(I)));

  }

  diff = vgetq_lane_u64(sum, 0) + vgetq_lane_u64(sum, 1);

  for (; i < len; ++i) {

    const int diff_y = ref[i] - src[i];

    const int new_y = (int)(dst[i]) + diff_y;

    dst[i] = clip_y_NEON(new_y);

    diff += (uint64_t)(abs(diff_y));

  }

  return diff;

}

static void SharpYUVUpdateRGB_NEON(const int16_t* ref, const int16_t* src,

                                   int16_t* dst, int len) {

  int i;

  for (i = 0; i + 8 <= len; i += 8) {

    const int16x8_t A = vld1q_s16(ref + i);

    const int16x8_t B = vld1q_s16(src + i);

    const int16x8_t C = vld1q_s16(dst + i);

    const int16x8_t D = vsubq_s16(A, B);   // diff_uv

    const int16x8_t E = vaddq_s16(C, D);   // new_uv

    vst1q_s16(dst + i, E);

  }

  for (; i < len; ++i) {

    const int diff_uv = ref[i] - src[i];

    dst[i] += diff_uv;

  }

}

static void SharpYUVFilterRow_NEON(const int16_t* A, const int16_t* B, int len,

                                   const uint16_t* best_y, uint16_t* out) {

  int i;

  const int16x8_t max = vdupq_n_s16(MAX_Y);

  const int16x8_t zero = vdupq_n_s16(0);

  for (i = 0; i + 8 <= len; i += 8) {

    const int16x8_t a0 = vld1q_s16(A + i + 0);

    const int16x8_t a1 = vld1q_s16(A + i + 1);

    const int16x8_t b0 = vld1q_s16(B + i + 0);

    const int16x8_t b1 = vld1q_s16(B + i + 1);

    const int16x8_t a0b1 = vaddq_s16(a0, b1);

    const int16x8_t a1b0 = vaddq_s16(a1, b0);

    const int16x8_t a0a1b0b1 = vaddq_s16(a0b1, a1b0);  // A0+A1+B0+B1

    const int16x8_t a0b1_2 = vaddq_s16(a0b1, a0b1);    // 2*(A0+B1)

    const int16x8_t a1b0_2 = vaddq_s16(a1b0, a1b0);    // 2*(A1+B0)

    const int16x8_t c0 = vshrq_n_s16(vaddq_s16(a0b1_2, a0a1b0b1), 3);

    const int16x8_t c1 = vshrq_n_s16(vaddq_s16(a1b0_2, a0a1b0b1), 3);

    const int16x8_t d0 = vaddq_s16(c1, a0);

    const int16x8_t d1 = vaddq_s16(c0, a1);

    const int16x8_t e0 = vrshrq_n_s16(d0, 1);

    const int16x8_t e1 = vrshrq_n_s16(d1, 1);

    const int16x8x2_t f = vzipq_s16(e0, e1);

    const int16x8_t g0 = vreinterpretq_s16_u16(vld1q_u16(best_y + 2 * i + 0));

    const int16x8_t g1 = vreinterpretq_s16_u16(vld1q_u16(best_y + 2 * i + 8));

    const int16x8_t h0 = vaddq_s16(g0, f.val[0]);

    const int16x8_t h1 = vaddq_s16(g1, f.val[1]);

    const int16x8_t i0 = vmaxq_s16(vminq_s16(h0, max), zero);

    const int16x8_t i1 = vmaxq_s16(vminq_s16(h1, max), zero);

    vst1q_u16(out + 2 * i + 0, vreinterpretq_u16_s16(i0));

    vst1q_u16(out + 2 * i + 8, vreinterpretq_u16_s16(i1));

  }

  for (; i < len; ++i) {

    const int a0b1 = A[i + 0] + B[i + 1];

    const int a1b0 = A[i + 1] + B[i + 0];

    const int a0a1b0b1 = a0b1 + a1b0 + 8;

    const int v0 = (8 * A[i + 0] + 2 * a1b0 + a0a1b0b1) >> 4;

    const int v1 = (8 * A[i + 1] + 2 * a0b1 + a0a1b0b1) >> 4;

    out[2 * i + 0] = clip_y_NEON(best_y[2 * i + 0] + v0);

    out[2 * i + 1] = clip_y_NEON(best_y[2 * i + 1] + v1);

  }

}

#undef MAX_Y

//------------------------------------------------------------------------------

extern void WebPInitSharpYUVNEON(void);

WEBP_TSAN_IGNORE_FUNCTION void WebPInitSharpYUVNEON(void) {

  WebPSharpYUVUpdateY = SharpYUVUpdateY_NEON;

  WebPSharpYUVUpdateRGB = SharpYUVUpdateRGB_NEON;

  WebPSharpYUVFilterRow = SharpYUVFilterRow_NEON;

}

#else  // !WEBP_USE_NEON

WEBP_DSP_INIT_STUB(WebPInitConvertARGBToYUVNEON)

WEBP_DSP_INIT_STUB(WebPInitSharpYUVNEON)

#endif  // WEBP_USE_NEON